1. Field of the Invention
The present invention relates to an animal feeder, and in particular, a feeder for continuous clean grazing.
2. Description of the Prior Art
Grazing in a field is a natural method for feeding farm animals. Throughout history, when grazing in a field was not easily available, animals (hereinafter xe2x80x9chorsesxe2x80x9d) have been fed in stalls or corrals with hay or other feed (hereinafter xe2x80x9chayxe2x80x9d) placed in a feed box and the horse is allowed to feed at its leisure. Such hay boxes are nothing more than a containment box with an open top, the opening allowing the horse to reach into the box from the top to get at the hay.
Several problems exist with this type of a hay box. First, a significant amount of hay inevitably spills onto the floor of the stall or ground. This loose hay results in a wasting of the hay as feed material, often results in the ingestion of contaminates by the horse as it eats hay from the floor of the stall, and creates additional work in cleaning the stall. An additional problem with prior hay boxes is that as the horse consumes the hay, the horse must continually reach further into the hay box to access the hay. Prior hay boxes also do not restrict the rate at which the horse can consume the hay. If hay is not continuously provided, the horse will often eat at an excessive rate when the hay is initially provided, resulting in potential digestion problems.
Improved devices for feeding horses were some of the earliest patented inventions. Initial horse feeders such as in U.S. Pat. No. 195,351 provided for a box with an adjustable bottom to move the food up to the top for the horse to feed so it wouldn""t have to reach further and further down as it consumed hay. This device required manual adjustment of the bottom as the horse consumed the hay.
U.S. Pat. No. 763,951 had a spring attached to the bottom of the surface the hay sat on so it would raise as the horse ate. However there was no way to determine, until the hay was gone, how much was left in the box because it was fully enclosed. Further, the bottom surface of the feeder was solid so contaminants, such as sand or gravel were trapped on the bottom surface and consumed by the animal.
A further feeder was described in U.S. Pat. No. 1,090,286, which had springs at the top pulling up the feeder as the animal ate the feed. This feeder has the same issues with contaminants and non-visibility of the feed level as U.S. Pat. No. 763,951. Further, it provided no attachment method to a stall wall so the horse could knock it over and eat freely from the floor, thereby consuming contaminants.
U.S. Pat. No. 4,294,197 described a horse feeder that could attach to the wall so the horse could not knock it over. However, the feeder was permanently attached to that wall and the bottom surface was still solid, causing contaminants to collect at the bottom of the food supply where the horse might still consume them.
From the above discussion, it is clear that the need exists for a hay feeder, which overcomes the above and other limitations of prior hay boxes. It is therefore a primary object of this invention to fulfill that need by providing a device which allows horses to graze on clean hay from a container maintained at a consistent height and which simulates grazing while the horse is contained.
Briefly described, these and other objects are accomplished according to the present invention by providing an adjustable spring-loaded hay grazing feeder that maintains the hay at a constant level for the horse to graze on, contains a pressure plate which is perforated to allow sand and other contaminants to fall out of the feeder, has a slot in the side to allow viewing of the amount of hay in the feeder, contains a removable grate so the opening size can be changed for different size horses (e.g. foals, draft horses), has mounting brackets that secure to various walls so the unit is portable and contains an anti-jamming feature by using flared walls at the top.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiments and the appended claims, taken in conjunction with the accompanying drawings.